[LTP] [PATCH 5/9] syscalls/fanotify10: Add more verifications and debug info

[Petr Vorel]

Hi Amir, all,

> Check that non-evictable inode ignore marks exist as expected
> and print mask of unexpected events.

> Fix information printed for events from unexpected pid.

Reviewed-by: Petr Vorel <pvorel@suse.cz>

...
> +++ b/testcases/kernel/syscalls/fanotify/fanotify10.c
...
> @@ -582,14 +591,18 @@ static void test_fanotify(unsigned int n)
>  	for (p = 1; p < num_classes && !tc->expected_mask_with_ignore; p++) {
>  		for (i = 0; i < GROUPS_PER_PRIO; i++) {
>  			ret = read(fd_notify[p][i], event_buf, EVENT_BUF_LEN);
> -			if (ret == 0) {
> +			if (ret >= 0 && ret < (int)FAN_EVENT_METADATA_LEN) {
>  				tst_brk(TBROK,
> -					"zero length read from fanotify fd");
> +					"short read when reading fanotify "
> +					"events (%d < %d)", ret,
> +					(int)EVENT_BUF_LEN);
Just for the record printing like this...

>  			}
> +			event = (struct fanotify_event_metadata *)event_buf;
>  			if (ret > 0) {
>  				tst_res(TFAIL, "group %d (%x) with %s and "
> -					"%s ignore mask got event",
> -					i, fanotify_class[p], mark->name, ignore_mark->name);
> +					"%s ignore mask got unexpected event (mask %llx)",
> +					i, fanotify_class[p], mark->name, ignore_mark->name,
> +					event->mask);
and this will be possible to avoid with macros include/tst_test_macros.h,
which prints them for free. FYI there can be also custom error text instead
of the failing syscall with parameters printed by default. But IMHO there should
be a reason to use it (mostly the default should be good enough, in case of
failure test reviewers will have to look into the test source anyway).

Kind regards,
Petr

>  				if (event->fd != FAN_NOFD)
>  					SAFE_CLOSE(event->fd);
>  			} else if (errno == EAGAIN) {